Reactions accompanying loss of coking ability during the aerial oxidation of coal

Significant loss of coking ability resulted from the aerial oxidation of a coking coal for 49 days at 60 °C and 32 days at 80 °C. No detectable change in the distribution of the extractable aliphatic hydrocarbons and only very minor changes in the distribution of the extractable aromatic hydrocarbons accompanied the oxidation. The virtually unchanged composition of the extractable hydrocarbons during oxidation and/or biodegradation and associated coking suggest these hydrocarbons play a very minor role, if any, in the coking process. A major role for the extractable polar compounds is indicated.